The 2014 online survey of 18,000 people in 18 countries gauged environmental attitudes and habits—and their sustainability—when it came to housing, transportation, food, and consumer goods. The first survey, released in 2008, included 14 countries. The latest survey, the fifth, includes consumers in Argentina, Australia, Brazil, Canada, China, France, Germany, Great Britain, Hungary, India, Japan, Mexico, Russia, Spain, South Korea, Sweden, the United States and, for the first time, South Africa.

The survey had questions on 65 topics. Respondents were asked things such as how important it was to own a luxury car or big house, whether they used disposable household products rather than things they needed to wash and reuse, whether it was important to know where their food was produced, and whether they kept the thermostat low to save energy.

Some major takeaways:

1. Some consumer behavior is improving.

In half the countries surveyed—Argentina, Australia, Great Britain, Hungary, India, Mexico, Russia, Sweden, and South Korea—people acted in more environmentally friendly ways than they had in 2012. For example, Russians are using more public transportation, and British consumers are buying more green electricity.

But five countries—Canada, China, Germany, Japan, and the United States—reported that people's habits were less sustainable than in the previous survey. Sixty-eight percent of Germans drink bottled water daily, and Canadians are among the most likely to own at least two cars or trucks.

2. Anxiety about the environment is growing.

A slim majority of consumers—51 percent—agree that global warming will negatively affect their own lives. Latin Americans are the most concerned, with more than three in four Brazilians convinced that climate change will impact them personally.

"We live in the land of plenty," NGS research manager Susan Frazier said of the prevailing attitude in many industrialized countries, "and to be completely crass about it, we don't worry about it much."

3. More people trust science.

Respondents in 11 of 18 countries show growing acceptance—68 percent—of the idea that human activity is the cause of climate change. But skepticism abounds in the industrial world. Japanese, British, and Australian consumers are dubious about the human link to global warming, and Americans bring up the rear as the most disbelieving.

That "doesn't surprise me, given the disinformation that we've seen" in the U.S. media, Whan says. "It's depressing that where the greatest per capita consumption happens, there seems to be the least willingness to change, adapt, and carry one's share of the load."

4. Americans resist going green.

As in every previous Greendex survey, Americans rank last overall in environmental attitudes and habits—except when it comes to food, where they're 15th.

Nearly one in four American households owns four or more TVs. Americans are also among the most likely to balk at paying extra for environmentally friendly products, and they consume more packaged and processed food than people in most other countries. And since the 2012 survey, more Americans are saying that they view owning a big house as an important goal in their lives.

5. Canada is on an unsustainable path.

U.S. consumers may be set in their unsustainable ways, but "Canadians are trying to catch up to Americans," Whan says. Canadian consumers scored as the next-to-worst environmental stewards in the survey and saw the largest decreases in environmentally healthy behavior since 2012.

As in past surveys, the worst offenders express the least guilt about the size of their environmental footprint. British, German, and Swedish consumers not only feel the least remorse but also are the most likely to say they won't change their ways—even after being told how low their country has scored on the Greendex.

"People in the north tend to point to government as being responsible rather than individuals," Whan says. "There's a lack of individual ownership of the problems."

7. Hope and untapped potential exists in the developing world.

The industrial world's ennui contrasts sharply with the attitude in large developing economies.

Consumers in India and China repeated their first- and second-place rankings from 2012. Indians topped every category except the one that included the types of products they buy, coming in second after South Koreans, who scored third highest overall. Two other emerging economies, Brazil and Argentina, rounded out the top five countries whose consumers had the greenest behaviors.

Although consumers in the greenest countries feel relatively helpless to do more, they're the most receptive to making an effort to do better. When given information about their personal impact on the environment, Mexicans, Brazilians, Indians, and Argentineans said they intended to change the way they live, by, for example, eating less meat.

Still, there are troubling signs as emerging economies grow wealthier. Chinese consumers are now most likely to say that owning a big house is a very important life goal. And more consumers in China, India, and Mexico reported driving alone than in 2012.

8. Repairing, reusing, and recycling are on the rise.

Majorities in 17 of 18 countries say they'd rather repair than replace a broken item, with Chinese and German consumers the most likely to fix something and Japanese consumers the least likely. American and French consumers are the most likely to buy used items; Canadian, British, and Australian consumers are the biggest recyclers.

Darnall says economic necessity may have played a role in reducing waste, but she hopes consumers will stick with their new routines long after the global recession is over.